Design of a 41.14-48.11 GHz triple frequency based VCO

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Growing deployment of more efficient communication systems serving electric power grids highlights the importance of designing more advanced intelligent electronic devices and communication-enabled measurement units. In this context, phasor measurement units (PMUs) are being widely deployed in power systems. A common block in almost all PMUs is a phase locked oscillator which uses a voltage controlled oscillator (VCO). In this paper, a triple frequency based voltage controlled oscillator is presented with low phase noise and robust start-up. The VCO consists of a detector, a comparator, and triple frequency. A VCO starts-up in class AB, then steadies oscillation in class C with low current oscillation. The frequency of the VCO, which is from 13.17 GHz to 16.03 GHz, shows that the frequency is tripling to 41.14-48.11 GHz. Therefore, its application is not limited to PMUs. This work has been simulated in a standard 0.18 µm CMOS process. The simulated VCO achieves a phase noise of -99.47 dBc/Hz at 1 MHz offset and -121.8 dBc/Hz at 10 MHz offset from the 48.11 GHz carrier

Aspects of Housing Development analysis of the impacts of social & economic issues on housing physical indicators (Case Study: The 2nd District of Tehran)

Housing development and the planning of it includes variant aspects, which are important to study, in order to have a successful plan in a city. Physical aspect contains scrutiny of seeming and objective factors of housing and dwellings, which includes kinds of building materials, quality of structure, urban accesses, and etc. Social aspect contains issues such as structure of population and household, cultural issues and etc. And economic aspect of housing include issues like cost of dwellings and real states, households’ incomes and etc. In addition, these aspects have influences on each other too. For example making changes in social and economic conditions will cause the change of physic of housing. Therefore, this paper studies impacts of social and economic situation on physic of housing in the 2nd District of Tehran as a bipolar area (in north and south of Hemmat expressway) which suffers a serious inequality in distribution of services and facilities, households’ income, cost of properties, cultural and social indicators and etc. So the relationship between physical aspect of housing and social and economic factors will be defined as a function by the two fallowing method: Factor-Analysis and Regression. This paper concludes that enhance of quality of housing is not achievable whit physical intervention merely and a comprehensive approach is necessary for housing planning

Design of a wideband doherty power amplifier with high efficiency for 5g application

This paper discusses the design of a wideband class AB-C Doherty power amplifier suitable for 5G applications. Theoretical analysis of the output matching network is presented, focusing on the impact of the non-ideally infinite output impedance of the auxiliary amplifier in back off, due to the device’s parasitic elements. By properly accounting for this effect, the designed output matching network was able to follow the desired impedance trajectories across the 2.8 GHz to 3.6 GHz range (fractional bandwidth = 25%), with a good trade-off between efficiency and bandwidth. The Doherty power amplifier was designed with two 10 W packaged GaN HEMTs. The measurement results showed that it provided 43 dBm to 44.2 dBm saturated output power and 8 dB to 13.5 dB linear power gain over the entire band. The achieved drain efficiency was between 62% and 76.5% at saturation and between 44% and 56% at 6 dB of output power back-off

High-Speed and Low-Power Flash ADCs Encoder

This paper presents a high-speed, low-power and low area encoder for implementation of flash ADCs. Key technique for design of this encoder is performed by convert the conventional 1-of-N thermometer code to 2-of-M codes (M = ¾ N). The proposed encoder is composed from two-stage; in the first stage, thermometer code are converted to 2-of-M codes by used 2-input AND and 4-input compound AND-OR gates. In the second stage by two ROM encoders, 2-of-M codes determine n-1 MSB bits and one LSB bit. The advantages of the proposed encoder rather than other similar works are high speed, low power consumption, low active area, and low latency with same bubble error removing capability. To demonstrate the mention specifications, 5-bit flash ADCs with conventional and proposed encoders in their encoder blocks, are simulated at 2-GS/s and 3.5-GS/s sampling rates in 0.18-μm CMOS process. Simulation results show that the ENOB of flash ADCs with conventional and proposed encoders are equal. In this case, the proposed encoder outputs are determined almost 30-ps faster rather than the conventional encoder at 2-GS/s. Also, the power consumptions of the conventional and proposed encoders were 17.94-mW and 11.74-mW at 3.5-GS/s sampling rate from a 1.8-V supply, respectively. Corresponding, latencies of the conventional and proposed encoders were 3 and 2 clock cycles. In this case, number of TSPC D-FFs and logic gates of the proposed encoder is decreased almost 39% compared to the conventional encoder

Estimating the odd-ratio of factors affecting households' exposure to catastrophic and impoverishing health expenditures

Aims: The main object of this study was to estimate the odd-ratio of factors affecting families' exposure to catastrophic and impoverishing health expenditures. Methods: This research was a cross-section study with a clustered sampling method. The sampling units were Tehran's households who had lived in Tehran for at least one year before the data collection. The data gathering tool was the WHO questioner. The Logistic model and the stata13 software were used for estimating the odd-ratio of the factors determining households' exposure to catastrophic and impoverishing health expenditures. Results: According to the results of this study, the presence of a family member older than 60, using inpatient services and informal payments increase the probability of catastrophic expenditures. This is while insurance coverages reduces this issue. Conclusion: According to the obtained results, extending the insurance coverage and the prepayment mechanism, preparing low cost inpatient services by the extension of prepayments, codifying health care packages under the commitment of insurance agencies, reforming the payment systems and monitoring tariffs can prevent households from falling under the poverty line. This means that it can help families to overcome their poverty in order to have better lives

Black discoloration of the knee articular cartilage in a patient with pigmented villonodular synovitis: A case report

Key Clinical Message In this case report, total knee arthroplasty was performed in a patient with pigmented villonodular synovitis. During surgery, severe black discoloration of the articular cartilage and menisci was observed in the patient. According to literatures, this is the first case report of severe articular cartilage pigmentation in a patient with pigmented villonodular synovitis